Electronic sensor with flexible sensing device

ABSTRACT

An electronic barrier alarm sensor having a flexible sensing device. The sensor may be mounted to a door, door frame, window, window frame, object or wall to detect when a door or window has been opened, that an object has been moved or to detect the presence of an animal. The flexible sensing device comprises one or more attributes that change as the flexible sensing device is bent, or unbent, by operation of a door, window, removal of an object, or the presence of an animal. Based on the changes, the electronic barrier alarm sensor may transmit an alarm signal when one or more measured values of the one or more attributes changes by more than one or more predetermined amounts.

BACKGROUND I. Field of Use

The present application relates to the field of sensing technologies.More specifically, the present application relates to a new type ofelectronic sensor.

II. Description of the Related Art

Electronic sensors are used in a variety of applications, such as homesecurity and industrial applications. In home security applications,electronic sensors take the form of door and window sensors, motionsensors, garage door sensors, glass break sensors, etc. For decades,door and window sensors have comprised two distinct parts: a magnet anda reed switch/transmitter assembly. The reed switch/transmitter assemblyis typically installed onto a stationary surface, such as a door orwindow frame, while the magnet is mounted to a movable portion of a dooror window. When the door or window is closed, the magnet and reed switchare in close proximity to one another, maintaining the reed switch in afirst state indicative of a “no alarm” condition. If the door or windowis opened, proximity is lost between the magnet and the reed switch,resulting in the reed switch changing state, e.g., from closed to openor from open to closed. The change of state is indicative of a localalarm condition, and a signal may be generated by circuitry locatedwithin the reed switch assembly and sent, via wires or over-the-air, toa central security panel or gateway in the home, which may forward thesignal to a remote monitoring station. In addition, a loud audible alertmay be generated, either at the central security panel in the home ordirectly by the circuitry within the reed switch assembly, indicatingthat a door or window has been opened.

One problem with prior art door and window sensors is the overall“footprint” of door and window sensors. It is desirable to make thefootprint as small as possible, because many people consider door andwindow sensors to be an eyesore, especially when each door and window ina home is outfitted with a sensor.

Another problem with having to use a magnet in a door or window sensoris cost. The cost of a magnet may approach one-fifth the overall cost ofa sensor. Removing the magnet would, thus, save 20% or more to the costof each sensor.

Another problem with prior art door and window sensors is that they canbe difficult to install, because the magnet and the reed switch assemblymust be closely aligned in order for these sensors to operate properly.

Yet another problem with prior art door and window sensors is that theycannot determine how far a door or window has been opened. They aregenerally only able to determine if a door or window is open or closed.

Prior art electronic sensors could also be used to detect when a thingof value has been moved. Again, a read switch assembly can be mounted toa movable thing of value with a corresponding magnet mounted to astationary object, such as a floor or a wall. When someone moves thething of value, magnetic contact is broken between the reed switchassembly and the magnet, and the reed switch assembly transmits a signalindicative of the movement. Such sensors also suffer from the samedeficiencies noted above.

SUMMARY

The embodiments described herein relate to an electronic sensor andmethod of operating the electronic sensor. In one embodiment, anelectronic sensor is described, comprising a flexible sensing deviceprotruding externally from a housing of the electronic sensor fordetecting when a barrier monitored by the electronic sensor has beenopened, a transmitter for transmitting an alarm signal to a receiver, amemory having processor-executable instructions stored thereon, and aprocessor, coupled to the flexible sensing device, the transmitter, andthe memory for executing the processor-executable instructions thatcause the electronic sensor to monitor, by the processor, an attributeof the flexible sensing device, generate, by the processor, the alarmsignal when the processor determines that a value of the attribute ofthe flexible sensing device has changed more than a predeterminedthreshold, and transmit, by the processor via the transmitter, the alarmsignal.

In another embodiment, a method of operating a barrier alarm sensor isdescribed, comprising monitoring, by a processor of the electronicsensor, an attribute of a flexible sensing device of the electronicsensor, the flexible sensing device protruding from a housing of theelectronic sensor, generating, by the processor, an alarm signal whenthe processor determines that a value of the attribute of the flexiblesensing device has changed more than a predetermined threshold, andtransmitting, by the processor via a transmitter coupled to theprocessor, the alarm signal.

BRIEF DESCRIPTION OF THE DRAWINGS

The features, advantages, and objects of the present invention willbecome more apparent from the detailed description as set forth below,when taken in conjunction with the drawings in which like referencedcharacters identify correspondingly throughout, and wherein:

FIG. 1 is an illustration of a partial home security system inaccordance with one embodiment of the principles discussed herein;

FIG. 2 is a close-up, isometric view of one of the electronic sensorsshown in FIG. 1 , configured for use on a door;

FIG. 3 is a side view of the electronic sensor as shown in FIG. 2 ,mounted to a surface such as a door frame, a door, or a surface, such asa table, desk, or wall;

FIG. 4 is a side view of the electronic sensor as shown in FIGS. 2 and 3, mounted to the surface as shown in FIG. 3 ;

FIG. 5 is a perspective, rear view of another one of the electronicsensors shown in FIG. 1 , configured for mounting to a window frame;

FIG. 6 is a functional block diagram of one embodiment of the electronicsensors shown in FIGS. 1-5 in accordance with the teachings herein; and

FIG. 7 is a functional block diagram of one embodiment of the electronicsensors as shown in FIGS. 1-6 in accordance with the teachings herein.

DETAILED DESCRIPTION

The present application relates to an electronic sensor for monitoringbarriers, such as doors, windows, garage doors, gates, etc., as well asfor use in providing notifications of activities, such as movement of anobject, monitoring to determine the presence of an animal, or for othermonitoring activities. The electronic sensor comprises a flexiblesensing device that protrudes from a housing of the electronic sensor.When the flexible sensing device is bent, for example, as a door isopened, the electronic sensor determines a change of a value of anattribute of the flexible sensing device, and then performs one or moreactions based on the value of the attribute. For example, the electronicsensor may transmit an alarm signal. The electronic sensor overcomesmany problems of prior-art, magnet-based sensors, such as elimination ofa magnet, resulting in a lower manufacturing cost, easier installation,and a reduction in the footprint of such sensors, thereby providing asensor that is more aesthetically pleasing.

FIG. 1 is an illustration of a security system using one or moreelectronic sensors in accordance with the principles discussed herein.In this embodiment, a door assembly 100 and a window assembly 102 aremonitored by electronic sensors 104 and 106, respectively. Each of theelectronic sensors comprises a housing 108 and a flexible sensing device110 protruding from each respectable housing.

In the example illustration of FIG. 1 , electronic sensor 104 is mountedto a door jamb 114 such that flexible sensing device 110 extends acrossa space 124 between door jamb 114 and a door edge 116 proximate to thedoor jamb. In other embodiments, electronic sensor 104 may be mounted todoor edge 116 such that flexible sensing device 110 extends across space124 and over a portion of door jamb 114. When door 12 is opened,flexible sensing device 110 is bent as door 112 acts upon flexiblesensing device 110, causing one or more attributes of flexible sensingdevice 108 to change. This/these change(s) are detected by processingcircuitry within housing 108 and the processing circuitry performs oneor more actions upon the one or more attributes exceeding one or morepredetermined values.

Electronic sensor 106 operates in a similar manner as electronic sensor104. In the example shown, housing 108 of electronic sensor 106 ismounted to a window frame 118, and flexible sensing device 110 protrudesfrom housing 108, extending across an area above upper frame member 120of a lower sash 122 of window assembly 102. When lower sash 122 israised, thus opening window assembly 102, upper frame member 120 bendsflexible sensing device upwards, in this embodiment, causing one or moreattributes of flexible sensing device 110 to change. This/thesechange(s) are detected by processing circuitry within housing 108 andthe processing circuitry performs one or more actions upon the one ormore attributes exceeding one or more predetermined values.

In another embodiment, a sensor the same or similar to electronicsensors 104 and 106 can be used to provide notifications of activities,such as movement of an object. For example, the sensor could be affixedto a valuable item, such as a television, portable computer, audioequipment, a valuable painting or artwork, etc. in order to determinewhen such an object has been moved. In this embodiment, the sensor isaffixed such that flexible sensing device 110 is bent against a hardsurface, such as a tabletop or a wall. If the object is moved, flexiblesensing device 110 straightens as the object is moved away from the hardsurface, causing one or more attributes of flexible sensing device 110to change. This/these change(s) are detected by processing circuitrywithin housing 108 and the processing circuitry performs one or moreactions upon the one or more attributes exceeding one or morepredetermined values.

In yet another embodiment, a sensor the same or similar to electronicsensors 104 and 106 can be used to monitor for the presence of ananimal. For example, the sensor could be affixed to a baseboard inside ahome, or to an exterior wall of a home, near the ground, to detect thepresence of rats or mice. These rodents tend to travel along walls, soplacing a sensor along suspected travel routes may indicate theirpresence if a rodent passes the sensor and brushes against flexiblesensing device 110. When a rodent passes the sensor, flexible sensingdevice 110 may be bent or deflected, causing one or more attributes offlexible sensing device 110 to change. This/these change(s) are detectedby processing circuitry within housing 108 and the processing circuitryperforms one or more actions upon the one or more attributes exceedingone or more predetermined values.

Referring back to FIG. 1 , electronic sensors 104 and 106 eachcommunicate with a receiver 126, such as a central security panel, awireless router, a wireless hub, a mobile phone, computer, etc.,typically by transmitting wireless RF signals generated by eachelectronic sensor. For example, if door 112 is opened, electronic sensor104 may transmit an alarm signal in the form of a wireless transmissionbased on, for example, the popular Z-wave® protocol, to receiver 126.The alarm signal comprises one or more of an identification of theparticular sensor reporting the alarm signal, a door or window status(i.e., “open”, “closed”), a velocity or acceleration of a door or window(based on the rate of change of the position or velocity of the door orwindow, as determined by detecting the rate of change of the one or moreattributes of flexible sensing device 110 by the internal processingcircuitry), and/or an estimate of a position of the door or window(i.e., half-way open/closed, 3 inches open, wide open, etc.).

FIG. 2 is a close-up, isometric view of electronic sensor 104,configured for use on a door. Flexible sensing device 110 is shownprotruding from housing 108 perpendicularly in a plane that is inalignment with a bottom surface (not shown) of housing 108. The lengthof flexible sensing device 110 is shown, in this example, to beapproximately the length of housing 108, but in other embodiments, thelength may vary depending on the application. The length of flexiblesensing device, in one embodiment, is 2.2 inches, although in otherembodiments, the length may be different. Also, in other embodiments,flexible sensing device 110 may extend from housing 108 at differentlocations other than the one shown in FIG. 2 , and/or at one of anynumber of angles and not necessarily perpendicularly.

FIG. 3 is a side view of electronic sensor 104 mounted to a surface 300,such as a door frame, a door, or a surface, such as a table, desk, orwall. Flexible sensing device 104 comprises an elastic material thatapplies a restoring force to flexible sensing device 104 when it is bentfrom its natural “quiescent” position. In the embodiment shown in FIG. 3, the quiescent position is shown as flexible sensing device 104 beingin a “flat” or “straight position. In another embodiment, the quiescentposition is a bent, or flexed position, such as the position shown inFIG. 4 . In either case, flexible sensing device 104 may be bent, orstraightened as the case may be as a door or window is opened or closed,an object is placed or removed in proximity to the sensor, or when ananimal comes into contact with the sensor.

Flexible sensing device 104 comprises one or more attributes, such as aresistance, a capacitance or an inductance, as measured across twoelectronic terminals of flexible sensing device 104 (not shown), such asa pair of solder tabs. For example, flexible sensing device 110 maycomprise a Flex Sensor FS, manufactured by Spectra Symbol Corp. of SaltLake City, Utah. This particular sensor comprises a “flat resistance” of10 k ohms, i.e., the resistance between the two electronic terminals is10 k ohms when the sensor is unflexed. The resistance of this particularsensor increases to at least 20 k ohms when the sensor is flexed 180degrees, i.e., with a tip of the sensor bent all the way to its base. Inother embodiments, an attribute of flexible sensing device 110 maydecrease in value when flexible sensing device 110 is flexed from thequiescent position. In the position shown in FIG. 4 , the resistance maybe approximately 15 k ohms, as flexible sensing device is bentapproximately halfway between the unbent position and the fully bentposition, as mentioned above. The resistance of flexible sensing device110 may change linearly or non-linearly as the sensor is flexed. Suchresistance is measured by the internal processing circuitry, eitherdirectly or indirectly, and compared to one or more predeterminedresistances in order to determine when a door has been opened. Indirectmeasurement of the attribute may be accomplished, in one embodiment, byusing a simple voltage divider, or some other well-known circuit, asdescribed later herein.

FIG. 4 is a side view of the electronic sensor 104 as shown in FIG. 3 ,mounted to a surface 300. However, in this view, flexible sensing device104 is shown as being bent, or deflected, by a second surface 400, suchas a door, window, object or animal, when electronic sensor 104 ismounted to a door jamb, a door, or a hard surface. As described above,flexible sensing device 110 may present a greater, or less, resistanceto the internal processing circuitry when flexible sensing device 110 isbent to the position as shown.

In one embodiment, the sensor shown in FIGS. 3 and 4 may be used inapplications other than security. For example, the sensor may be used tomonitor the status of a valuable object, such as a TV, computer, work ofart, etc. The sensor may be attached, via pressure-sensitive adhesive,Velcro®, or some other well-known temporary or fixed adhesive means, toa valuable object, or to a static surface such as a floor, wall, desk,or table in proximity to where a valuable object may be located. Ineither case, flexible sensing device 110 may be bent to the positionshown in FIG. 4 as the valuable object is set in place on a floor, wall,desk or table against flexible sensing device 110. Then, if the valuableobject is moved, flexible sensing device 110 springs back to itsquiescent form, in this example “straight”, as shown in FIG. 3 , by arestoring force of flexible sensing device 110, as the valuable objectis no longer in place to hold flexible sensing device 110 in the flexedposition. When flexible sensing device 110 returns to the quiescentposition via the restoring force after the valuable object has beenremoved, internal circuitry detects a change in one or more values ofone or more attributes of flexible sensing device 110, such as itsresistance, and transmits an alarm signal when one or more of the valuesmeet, exceed, or fall below, one or more predetermined thresholds. Inthis way, the sensor monitors against potential theft of the valuableobject.

In another example, the sensor shown in FIGS. 3 and 4 may be used tomonitor for the presence of animals and, in one embodiment inparticular, rodents. In this application, the sensor may be affixed tothe bottom of a wall where rodents are suspected, as rodents typicallytravel along walls. When a rodent passes the sensor, the rodent's bodydeflects or bends flexible sensing device 100, causing one or moreattributes to change. This change is detected by the internal processingcircuitry, and the sensor may transmit a message indicative of apotential rodent.

FIG. 5 is a perspective, rear view of electronic sensor 106 in anotherembodiment, configured for mounting to a window frame, such as a singlehung window having a fixed first portion and a slidable second portion.In this embodiment, flexible sensing device 110 extends perpendicularlyfrom a rear surface 500 of housing 108, in one embodiment, in a planeparallel to a left surface 502 of housing 108. In this embodiment, therear surface 500 is affixed to a window frame with flexible sensingdevice 110 extending into open space that allows the slidable secondportion of the window to move. When the window is opened, flexiblesensing device 110 is bent by the slidable portion, causing one or morevalues of one or more attributes of flexible sensing device 110 tochange. When a value of an attribute changes more than a predeterminedamount, or when the value reaches a predetermined threshold, an alarmsignal is transmitted to receiver 126.

Receiver 126 comprises one of a number of electronic devices capable ofcommunications with electronic sensor 104 or 106. Receiver 126 maycomprise a central security panel, a gateway, a hub, or a node of amesh-network. Receiver 126 may be coupled to a wide-area network 128,such as the Internet, in order to relay signals from electronic sensor104 or 106 to a remote location, such as remote receiver 130. Remotereceiver may comprise a central security monitoring center, a mobilephone, a computer, or some other electronic end device.

FIG. 6 is a functional block diagram of one embodiment of electronicsensor 104 or 106 in accordance with the teachings herein. Specifically,FIG. 6 shows processor 600, memory 602, flexible sensing device 110,transmitter 604 and sensing circuitry 606. It should be understood thatthe functional blocks may be coupled to one another in a variety ofways, and that not all functional blocks necessary for operation of theelectronic sensor are shown (such as a power supply), for purposes ofclarity.

Processor 600 is configured to provide general operation of theelectronic sensor by executing processor-executable instructions storedin memory 602, for example, executable code. Processor 600 typicallycomprises a general purpose processor, such as an ADuC7024 analogmicrocontroller manufactured by Analog Devices, Inc. of Norwood Mass.,although any one of a variety of microprocessors, microcomputers, and/ormicrocontrollers may be used alternatively. Due to the relative smallsize of electronic sensors, and the fact that most electronic sensorsare battery-powered, processor 300 is typically selected to have lowpower consumption, small in size, and inexpensive to purchase.

In one embodiment, processor 600, memory 602 and transmitter 604 arecombined into a single module, such as the case with a Z-Wave 700 seriesZGM130S SIP Module in an embodiment that utilizes the Z-wave 700protocol. The ZGM130S SIP Module allows mesh-type, wirelesscommunications between sensor 104/106 and receiver 126, either directlyor through one or more other Z-Wave devices. In another embodiments,other system-on-chip modules provide functionality in place of processor600, memory 602 and transmitter 604, supporting other commonmesh-network protocols such as Zigbee®, RF4CE, 6LoWPAN, WirelessHARTEnOcean, ISAIOO.lla, IEEE 802.15.4 and/or others.

Memory 602 comprises one or more information storage devices, such asRAM memory, ROM memory, EEPROM memory, UVPROM memory, flash memory, SDmemory, XD memory, or other type of electronic, optical, or mechanicalmemory device. Memory 602 is used to store processor-executableinstructions for operation of the electronic sensor as well as anyinformation used by processor 600, such as threshold information andidentification information. Memory 602 excludes propagating signals.

Transmitter 604 comprises circuitry necessary to wirelessly transmitalarm signals and/or other information from electronic sensor 104/106 toreceiver 126 or a gateway device coupled to a wide area network such asthe Internet, either directly or through in intermediate device, such asa repeater, commonly used in popular mesh networks. Such circuitry iswell known in the art and may comprise BlueTooth, Wi-Fi, RF, optical,ultrasonic circuitry, among others. In an alternative embodiment,transmitter 604 comprises a transceiver, for wirelessly sending alarmsignals and other information, and for receiving information fromreceiver 126 and/or other devices.

Sensing circuitry 606 comprises hardware and/or firmware to determineone or more values of one or more attributes of flexible sensing device110. Attributes such as resistance, capacitance and inductance generallycannot be measured directly by processor 600, thus the need, in someembodiments, for such sensing circuitry 606. In one embodiment, sensingcircuitry comprises a voltage divider, comprising a first resistorwithin housing 108, having a first end coupled to processor 600 and asecond end coupled to ground and flexible sensing device 110 forming asecond “resistor” that has a first terminal coupled to the first end ofthe first resistor and a second terminal coupled to a power sourcewithin housing 108. In this example, as the resistance of flexiblesensing device 110 changes, so too does the voltage at the junction ofthe first resistor, flexible sensing device 110 and the second resistor.

FIG. 7 is a flow diagram illustrating one embodiment of a methodperformed by electronic sensor 104 or 106 for monitoring a door, window,object or the presence of an animal. While the method is described interms of electronic sensor 104 monitoring a door, it should beunderstood that the teachings therein can apply to electronic sensor106, and in either case, to applications other than security monitoring.It should also be understood that in some embodiments, not all of thesteps shown in FIG. 7 are performed, and that the order in which thesteps are carried out may be different in other embodiments.

At block 700, processor 600 monitors flexible sensing device 110, eitherdirectly or indirectly, to determine if there has been a change of oneor more values associated with one or more attributes of flexiblesensing device 110. Such attributes comprise a resistance, acapacitance, an inductance, or some other electronic, physical ormagnetic attribute of flexible sensing device 110. In this example,flexible sensing device 110 comprises a 2.2 inch flexible sensing devicesold by Sparkfun Electronics, comprising a resistance of 10 k ohms whenthe flexible sensing device is in a static, i.e., non-bent, condition.The resistance of flexible sensing device 110 may be determinedempirically by using flexible sensing device 110 as part of a voltagedivider circuit. Processor 600 measures a voltage of the voltagedivider, which is reflective of the resistance. In one embodiment,processor 600 measures the voltage divider voltage at periodicintervals. For example, processor 600 may remain in a quiescent,low-power state until it is time to measure the voltage once every 100ms.

In other embodiments, processor 600 determines one or more values of oneor more attributes of flexible sensing device 110 using othertechniques, with or without the use of sensing circuitry 606. Suchtechniques are generally known to those skilled in the art.

At block 702, the door being monitored by electronic sensor 104 isopened.

At block 704, as the door begins to open, processor 600 determines thatone or more of the values associated with the one or more attributes hasbegun to change, as flexible sensing device 110 begins bending as thedoor is opening. In one embodiment, a voltage from a voltage dividerbegins to decrease as the resistance of flexible sensing device 110begins to increase.

At block 706, processor 600 determines that the door or window has beenopened by comparing the one or more values of the one or more attributesof flexible sensing device 110 to one or more predetermined thresholds.Continuing with the given example, processor 600 may compare the voltagefrom the voltage divider to a predetermined voltage value stored inmemory 602, and when the voltage from the voltage divider meets orexceeds, or drops below, the predetermined voltage, processor 600determines that the door has been opened.

In one embodiment, the predetermined threshold for determining when thedoor has been opened can be programmable in order to give a user morecontrol over when to be notified of an opening. For example, a usercould use a smart phone or a user-interface of electronic sensor 104 toenter a threshold value in the form of a voltage or, more likely, in theform of a distance that the door may be opened before triggering analarm. For example, a user may set the threshold value so that “open”means a door or window opening more than 6 inches, one foot, etc., sothat users may open doors a small amount for letting air circulate, forexample, without triggering transmission of an alarm signal. In thisembodiment, processor 600 receives the threshold information from awireless transceiver coupled to the processor, or via a user interface(i.e., one or more pushbuttons, knobs, or some other mechanical orelectronic interface), and stores the threshold in memory 602.

In another embodiment, processor 600 may calculate a velocity and/oracceleration of the door, based on the rate of change of the position,or velocity, of the door as it is being opened. In this embodiment,processor 600 uses two or more values of one or more attributes offlexible sensing device 110 to make the calculation, based on well-knownprinciples. The velocity and/or acceleration may be compared tothreshold velocity and/or acceleration values stored in memory 602, andwhen they are met or exceeded, or fall below, processor 600 may transmitan indication that a violent break-in has occurred. In a relatedembodiment, processor 600 may transmit an indication that the door isbeing opened “normally” or “slowly”, based on a comparison of thevelocity and/or acceleration values to threshold values stored in memory602. For example, if the velocity of the door is greater than 0.5ft/sec, but less and 1.0 ft/sec, processor 600 may transmit an alarmsignal indicating that the door has been opened, and that the velocityof the opening is “normal”. If the velocity of the door is less than 0.5ft/sec, processor may indicate that the door has been opened “veryslowly”. If the velocity of the door is calculated to be greater than,say, 2.0 ft/sec, and/or attained an acceleration of 1.5 ft/sec²,processor 600 could indicate that the door was opened “quickly” or“violently”.

At block 708, in response to determining that the door has been opened,processor 600 performs one or more actions, such as to transmit an alarmsignal to receiver 126 and/or provide an audible and/or visual alert viaan indicator and/or speaker. The alarm signal typically comprises anidentification of the sensor transmitting the alarm signal, such as aserial number of the sensor stored in memory 602, a door status (i.e.,“open”, “closed”), a velocity and/or acceleration of the door, and/or anestimate of a position of the door (i.e., half-way open/closed, 3 inchesopen, wide open, etc.).

At block 710, in one embodiment, processor 600 may, additionally oralternatively to the alarm signal, transmit an indication of one or moremeasured values of one or more attributes of flexible sensing device110. For example, processor 600 may transmit the determined voltage ofthe voltage divider for processing by receiver 126. Receiver 126 may usethe voltage from the voltage divider to calculate how for the door orwindow has been opened, and provide that information to a user, eitherlocally via a local-area network (such as a Wi-Fi network), or viawide-area network 128. The receiver may calculate how far the door orwindow is open by using a lookup table, stored in a memory of receiver126. The lookup table could have a column of ascending or descendingvoltage values, each one with a corresponding estimate of how far thedoor or window is open, or an angle at which the door is open.

Also in this embodiment, a user can program receiver 126 using awireless device such as a smart phone, or a user interface of receiver126, to set various thresholds for electronic device 104, as well as forother electronic devices located throughout a home or business. Thethresholds may be in the form of a voltage, current, capacitance,inductance, etc., or in the form of a distance, such as 1 inch, 6inches, half-way open, etc. In one embodiment, alarm signals from eachelectronic device can be evaluated by receiver 126 to determine if auser should be notified of each alarm signal. For example, eachelectronic sensor can be assigned its own threshold(s), stored in amemory of receiver 126, so that when alarm signals are received byreceiver 126, receiver 126 can determine whether or not to alert a user.For example, when receiver 126 receives an alarm signal from a firstelectronic device 104 monitoring a first door, where the alarm signalcomprises one or more measured values of one or more attributes offlexible sensing device 110, receiver 126 compares the one or moremeasured values received from the first electronic device 104 anddetermines, based on the user-provided threshold(s) stored in its memoryin association with the second door/second electronic device 104, toalert a user when a user-provided threshold is set to 1 inch.Alternatively, when receiver 126 receives an alarm signal from a secondelectronic device 104 monitoring a second door, where the alarm signalcomprises one or more measured values of one or more attributes offlexible sensing device 110, receiver 126 compares the one or moremeasured values received from the second electronic device 104 anddetermines, based on the user-provided threshold(s) stored in its memoryin association with the second door/second electronic device 104, toignore the alarm signal when a user-provided threshold is set to 6inches.

At block 712, processor 600 may, additionally or alternatively to theabove, transmit an indication of how far the door has been opened, or aposition, such as an angle, based on information stored in memory 602.For example, the lookup table as described above could be stored withinmemory 602. If, for example, the measured voltage from a voltage divideris 1.8 volts, processor 600 may consult the lookup table and locate avoltage in the lookup table closest to 1.8 volts, and read acorresponding estimate of how far the door or window has been opened,for example, 6 inches, one foot, fully open, half-way open, etc.

At block 714, processor 600 may determine that the door or window hasbeen placed into a closed position based on one or more values of theone or more attributes of flexible sensing device 110. For example, whena door or window has been closed, flexible sensing device 110 revertsback to its quiescent state, for example, unbent, and, using the examplepreviously, the voltage from the voltage divider increases as theresistance of flexible sensing device 110 decreases as the door orwindow moves towards the closed position. Like before, processor 600 mayperiodically compare the value of one or more attributes of flexiblesensing device 110 to one or more predetermined thresholds to determinewhen the door or window has been closed, and/or to determine the door'svelocity and/or acceleration during closing. This threshold may be thesame or different than the predetermined threshold to determine when thedoor has been opened. For example, a user may set electronic sensor 104,or receiver 126, to alarm when the door has been opened more than 6inches, but to indicate that the door or window has been closed onlywhen the door or window is fully closed.

At block 716, in response to determining that the door or window hasbeen closed, processor 600 causes an indication that the door or windowhas been closed to be transmitted via transmitter 604 to receiver 126.In one embodiment, processor 600 calculates the velocity and/oracceleration of the door as it was being closed and provides thatinformation to receiver 126.

The methods or algorithms described in connection with the embodimentsdisclosed herein may be embodied directly in hardware or embodied inprocessor-readable instructions executed by a processor. Theprocessor-readable instructions may reside in RAM memory, flash memory,ROM memory, EPROM memory, EEPROM memory, registers, hard disk, aremovable disk, a CD-ROM, or any other form of storage medium known inthe art. An exemplary storage medium is coupled to the processor suchthat the processor can read information from, and write information to,the storage medium. In the alternative, the storage medium may beintegral to the processor. The processor and the storage medium mayreside in an ASIC. The ASIC may reside in a user terminal. In thealternative, the processor and the storage medium may reside as discretecomponents.

Accordingly, an embodiment of the invention may comprise acomputer-readable media embodying code or processor-readableinstructions to implement the teachings, methods, processes, algorithms,steps and/or functions disclosed herein.

While the foregoing disclosure shows illustrative embodiments of theinvention, it should be noted that various changes and modificationscould be made herein without departing from the scope of the inventionas defined by the appended claims. The functions, steps and/or actionsof the method claims in accordance with the embodiments of the inventiondescribed herein need not be performed in any particular order.Furthermore, although elements of the invention may be described orclaimed in the singular, the plural is contemplated unless limitation tothe singular is explicitly stated.

I claim:
 1. A method, performed with an electronic sensor having ahousing and a flexible sensing device protruding from the housing,comprising: securing the housing to a first portion of a barrier withthe flexible sensing device extending into a space into which a secondportion of the barrier may be moved; monitoring, by the electronicsensor, an attribute of the flexible sensing device of the electronicsensor; generating, by the electronic sensor, an alarm signal when aprocessor determines that a value of the attribute of the flexiblesensing device has changed more than a predetermined threshold; andtransmitting, via a transmitter of the electronic sensor, the alarmsignal.
 2. The method of claim 1, wherein the flexible sensing devicecomprises a length of flexible material and an electrical connector forcoupling the flexible sensing device to the processor.
 3. The method ofclaim 2, wherein the attribute is a resistance of the flexible sensingdevice.
 4. The method of claim 2, wherein the attribute is a capacitanceof the flexible sensing device.
 5. The method of claim 2, wherein theattribute is an inductance of the flexible sensing device.
 6. The methodof claim 2, wherein the value of the attribute changes as the flexiblesensing device is bent by the second portion of the barrier beingmonitored by the electronic device as the second portion of the barrieris moved into the space.
 7. The method of claim 2, wherein the firstportion of the barrier is a door jamb and the second portion of thebarrier is a door edge proximate to the door jamb.
 8. The method ofclaim 2, wherein the first portion of the barrier is a window casing andthe second portion of the barrier is an upper frame member of a lowersash of a window.
 9. The method of claim 1, wherein the predeterminedthreshold comprises a threshold value that allows the second portion ofthe barrier being monitored by the electronic sensor to be opened apredetermined amount without generating or transmitting the alarmsignal.
 10. The method of claim 1, further comprising: determining, bythe electronic sensor, how far the second portion of the barrier beingmonitored by the electronic sensor is open based on the value of theattribute.